Disable closed loop and tune for lean cruise?

[bradsm87]

Hi,

On other vehicles of my own, i've had measurable improvements in fuel economy by running around 15.6-15.8:1 AFR in light load and cruise due to reduced pumping losses.

I'll have NN disabled and closed loop coolant temp threshold set very high as not to go into closed loop.

Would I be best to modify the "FA Stoich" tables (and add to PE to get PE AFR back to normal) to trick the ECU into thinking it needs less fuel to get what it thinks is stoich then tune the VE tables or should I just leave the FA Stoich and PE tables stock and just go straight to tuning the VE table to get my desired AFRs?

Thanks in advance!

[Hemituna]

I'd leave 'FA Stoich' to its main purpose which is FA ratio for fuel type.

As you only want to change fuelling at cruise, use the VE table in the cells that are applicable.

Then the rest of the tune is still correct and if you ever change fuel...to say E10 or E30 or whatever you can just alter 'FA Stoich' and rock on!